1. Technical Field
This invention relates generally to methods, systems and apparatus for managing digital communications systems.
2. Description of Related Art
Digital subscriber line (DSL) technologies provide potentially large bandwidth for digital communication over existing telephone subscriber lines (twisted pairs of wires that are also may be referred to as loops and/or the copper plant). DSL systems can adjust to the characteristics of the subscriber line by using a discrete multitone (DMT) line code that assigns a number of bits to each tone (or sub-carrier), which can be adjusted to channel conditions determined during training/initialization of the modems (typically transceivers that function as both transmitters and receivers) at each end of the loop.
The performance of DSL systems is very often limited by the effects of crosstalk noise at the DSL receivers. Such crosstalk noise originates from sources that may include other DSL systems, or other systems whose signals are coupled on the twisted pairs used by DSL systems. Crosstalk noise is particularly strong when twisted pairs are physically close, such as when they share a common binder. Knowledge of crosstalk effects is very useful for DSL management operations, because it helps with identifying the cause of poor performance, and because it can lead to steps to correct the crosstalk problem.
Systems, apparatus, methods and techniques that provide improvements for performing identification of crosstalk within the twisted pairs of a binder or other group of communication lines would represent a significant advancement in the art. Also, systems, apparatus, methods and techniques for implementing such binder identification that can identify the crosstalk “victims” and the crosstalk “offenders” likewise would represent a significant advancement in the art.